Knitted fabric



June 24, 1958 J. E. MORGAN KNITTED FABRIC F iled May 16, 1957 3Sheets-Sheet 1 H CKKKTTTKK CKKKTTTKK TTKKKKKT TTKKKKKT KKKTTTKK CKKKTTTK.DTTKKKKKT DTTKK KKT 23 5678 FIG.5

INVENTOR N .A. G R O T M mu E. M M Mm E M D m .US v T W R. m M R LD N DTC Wu S E m m G F m. y m m MTH m CTT s M Dm W E x M m a S E N D N T E X LT Mm mm m w w R K D D A-TTORNEY N -O -l -NUMBER OF KNIT COURSES June 24,1958 J. E. MORGAN 2,839,909

KNITTED FABRIC Filed May 16, 1957 v 3 Sheets-Sheet 2 FIG. 3

D D C C D D C C 20 2| 20 2| 26 I 25 Z6 Z5 INVENTQR JOHN E MORGANATTORNEY June 24, 1958 J MORGAN 2,839,909

KNITTED FABRIC Filed May 16, 1957 5 Sheets-Sheet 3 JOHN E MORGAN Mow,

. needle banks.

United States Patent The present invention relates to the knitting ofairentrapping fabrics which are suited for use in the production ofgarments such as underwear and which, be-

cause of the cellular configuration or shape of the fabric isparticularly adapted to provide warmth. The invention includes thetreatment of the knitted product to enhance its hand and softness andalso its Warmth retaining character. The invention also includes the newheat insulating fabric which is produced by the invention, both beforeand after treatment thereof to enhance the softness and heat insulatingquality thereof.

The invention is particularly directed to the production of light weightknitted fabrics which are not irritating to the skin of the wearer andwhich have a multitude of air-entrapping cells formed therein, thesecells being retained to continue the insulating excellence of the fabricdispite prolonged wear.

In accordance with the present invention, a fabric is knitted upon a ribknitting machine having opposed Preferably, the needles areindependently mounted on each of the needle banks in groups with thegroups of needles on each of the needle banks being positioned betweenthe groups of needles on the opposed needle bank.

The rib knitting machine under consideration is operated by producingtuck stitches on one of the needle banks while the needles of theopposite needle bank are knitting in conventional fashion. After this isdone for a plurality of courses, the operation of the machine isreversed and the needles which produced tuck stitches are cauesd to knitin conventional fashion while the needles which formerly knitted inconventional fashion are caused to produce tuck stitches. This latteroperation is also performed for a plurality of courses. The operation ofthe machine is thus switched back and forth so that the pattern ofknitting is reversed every several courses.

It will be understood that when tuck stitches are produced, that theneedles are projected insufficiently to cast-off the yarn loops thereonand that the number of yarn loops in the hook of the needle increaseswith each successive pass of a yarn feed, e. g., with each successivecourse of knitting. When the needles of one of the needle banks whichhave been moved through several courses of tuck stitches are finallyknitted in conventional fashion, all of the yarn loops carried by theneedle at the time are simultaneously knitted off. Since a rib knittingmachine is used so that there are opposed needle banks, and because theoperation is periodically reversed, the knitting off of a plurality ofyarn loops is performed alternately by the needles of each of theopposing needle banks. 7

As will be appreciated, each successive knitting off of a plurality ofyarn loops is effected in the opposite direction (an inherentcharacteristic of the use of opposed needle banks as in rib knitting).The yarn loops which are knitted off as a result of the tuck stitchesextend transversely across the knitted product between intended toillustrate the invention as 2,839,909 Patented June 24, 1958 ICClongitudinally extending ribs and overlie longitudinally extendingtroughs of valleys. The longitudinal ribs form the sides of theair-entrapping cells and the tuck stitches form the bottom and top wallsof these cells. When the fabric is turned inside out, the troughs orvalleys become the longitudinal ribs for the back side of the fabric andthe longitudinal valleys of the front side become the ribs. The tuckstitches from the other needlebank form the bottom and top walls of thecells on the back side of the fabric. 7

It is to be particularly noted that the opposed'needles are arranged ingroups andare not constituted, in accordance with preferred practice ofthe invention, by single needles disposed between adjacent needles ofthe opposite needle bank. This is of importance because when the tuckstitches are formed by adjacent needles on the same needle bank, only alimited length of yarn is used and when these tuck stitches are knittedoff the loops so formed are stretched between adjacent longitudinal ribsand function to draw these ribs together at spaced apart points alongthe length thereof. This serves to accentuate the cellular constructionwhich is produced. At the same time, the tuck strands underlie the ribsand function to brace and maintain the height of these ribs when thefabric is stretched or subjected to prolonged wear.

A feature of the invention is the manner in which the knitted cellularfabrics of the invention are treated, not only to cleanse the fabric,but to nap itin a manner which facilitates the entrapment of air withinthe: cells of the fabric.

As will be seen more fully hereinafter, the knitted fabrics of theinvention define cells the walls-of which are of varying height. Moreparticularly,-there are side Walls constituted by longitudinallyextending knitted ribs and transverse ridges which constitute the topand bottom walls of each cell. These transverse ridges are constitutedby superposed tuck'strands which are of lesser height than thelongitudinal ribs. In accordance with th e invention, the yarns comprisefibrillatable fibers and the knitted fabric is treated to raise a napthe fibrillations of which extend in all directions from the crests ofthe ribs and from the outer tuck strands to enhance; the ability of thecells which are knitted to entrap air. Since the outer tuck strands arelower than the longitudinalribs, there is provided fibrillations at twodifferent levels.

The treating procedure broadly involves cleaning or scouring the knittedproduct as by passing the fabric through an aqueous bath containing adetergent or solvent for the grease, size or other foreign substanceswhich may be present, drying the fabric while preferably tum.- bling thesame so that the dried fibers are not all aligned and then napping thesurfaces of the drum-dried fabric to fibrillate the yarns or strands atthe crests of the longitudinal ridges and at the outer surface of theouter tuck strands.

The invention will now be more fully. described in conjunction with theaccompanying drawings which are applied to a 2 X 2 rib knitting machine.i

Fig. l'is a diagrammatic view illustratinga portion of a circularknitting machine having a pair of opposed I needle'banks, e. g., acylinder anda dial, and showing the positioning of the needles for 2 x 2rib knitting.

Fig. 2 is a chart indicating the operation of the dial and cylinderneedles in successive knitting courses, this knitting sequence of Fig.2, the view being on a greatly enlarged scale so that the knittedstructure which is produced can be more easily understood.

Fig. 4 is a photograph of the knitted product, the photographrepresenting an enlargement of 16 times.

Fig. 5 is a schematic view of flow-sheet character illustrating thesequence of treatment to which the knitted product of Fig. 4 issubjected for the:purpo'se "ofyen Fig. 6 is a photograph, similar toFig. 4, ai1d showing the knitted product after treatment as indicated inFig. 5.

Referring to Fig. 1, it will be seen that there is employed inaccordance with the invention a rib knitting machine having a pairof'opposed needle banks. Since the invention is particularly adapted forapplication to circular knitting machines one of the needle banks isidentified by the letter C to indicate that it is the cylinder of acircular knitting machine and .the other needle bank is identifiedby theletterD to indicate that it is the dial of a circular knitting machine.

It is desired to immediately make it clear that the invention is-notlimited to circular or even to continuous knitting ;so long as there areopposed needle banks. Normally there will be two needle banks inaccordance with the inventionbut this does not exclude the presence ofadditional needle banks so long as'alternate groups of opposed needlesare positioned to knit o. in opposite directions. The invention can evenbe performed with machines such as links and links machines in which theneedles may -be operated from either of two aligned needle beds (usuallyaxially spaced apart cylinders) so long as alternate groups of needlesare operated to knit off" in oppositedirections. V

It will be observed that the needles 10 of the cylinder C are arrangedin pairs. In brief, the cylinder C does not have a full complementofneedles (or if it does some of the needles must be held inoperative). Atthe same time, the needles 11 of the dial D are also arranged in pairs.It will be observed that each pair of cylinder needles 10 are disposedbetween each pair of dial needles 11 and vice versa. This is a 2 x 2 ribknit needle position.- -Fig. 1 also indicates the presence of combing 12so that the needles 10 and 11 willhave something to draw against'whenknitting is performed in conven-. tional manner. a

The use of pa rs of opposed needles is preferred but is not essential tothe invention. When each group of opposed needles is constituted bythree adjacent needles (a 3 x 3 rib knit needle positioningLthenthe'ribs and valleys will be wider. The'opposed groups-of needles neednot have the same number of needles and a 2 x 3 or a 2 x 4 or a 3 x 4rib knit needle positioning may be employed. It is even withinthe scopeof the invention to employ a l X 1 10i 1 x2 rib knit needle positioningbutthc cell formation is not nearly as deep and 'as well defined.. It isstressed that the 2 x 2 rib knit needle positioning which is preferredis uniquely superior in providing superior cell'forrnation andconsequent-air entrapment and this is so with particular emphasiswhenthe. 2 2 positioning is compared with a "l x 1 orfeven a 116i 21positioning.

. Fig.2 shows a preferrediknitting sequence .in laccordance'wlth'the'invention. It will be observed that in general, when thedial needles are; knitting conventionally,

that the cylinder needles produce tuckfs'titches,and vice versa; It willalso be observed that "the 7 dial needles knit conventionalstitches' fora "plura'lityo'f consecutive courses and. then knit tuck stitc'lies forapluralityoficonsecutlve courses. i

'In the preferred sequence of FigL Z Qthe 'neEdles knit five 1conventional stitches {and then "three-tuck; stitches.

is knitted by the needles of one of the needle banks is performed at thesame time that the needles of the other needle bank are performing theirfirst conventional stitch. This constitutes preferred operation of theinvention and leads to the production of a knitted product which'is ofparticularly uniformshape. However, the specific sequence of Fig. 2 isnot essential to the invention although it does illustrate the best modeof practicing the invention as itis presently understood.

Referring specifically to Fig. 2, the vertical columns labeled D and Crefer to individual needles on the dial and the cylinder respectively.The horizontal columns numbered 1, 2, 3, etc., identify consecutiveknitting courses.

The letter K identifies a conventionally knit stitch in which the needleis projected sufficiently to cause the old yarn loop to move rearwardlyfor a sufiicicnt distance to open the needle latch and to be cast offupon the body of the needle to the rear of the opened latch. The needleis then normally partially retracted to move the yarn forwardly topartially close the latch (a tuck position) and fresh yarn is placed inthe hook of the needle. The needle is then fully retracted within theneedle bed to cause the oldyarn loop to be knitted off" the needle andto draw the new yarn loop to the extent desired.

It will be understood that the foregoing depicts typical conventionalknitting and is presented as illustrative of the invention and not aslimiting the same. If a plurality of old yarn loops are present on theneedle at the beginning of the conventional knitting sequence, as theresult of previous tuck stitches. then all of these old yarn loops willbe simultaneously cast off during needle projection the needleprojection is insufficient to cause the old yarn As will be evident;when{the-first coiiventional stitch-is knitted, four yarn loop's will beknnteasrr at the same time. Three of th'e yar n loopsffbrm tiiek strands-It will i lastly be "se e'n tha t tlie last cohv entiofial' stitchwhich loop or loops to be cast off to the rear of the latch. When theneedle is then retracted, no yarn loop is knit off and the yarn loopsaccumulate within the hook portion of the needle. The needle may befully rctracted or preferably only partially retracted to minimizedrawing of the fresh yarn. It will be appreciated that any slack istaken up by the drawing action of the opposing needles of the oppositeneedle bank which knit conventionally while the needles of the otherneedle bank are producing tuck stitching.

The cammingneccssary for each of the foregoing operations is a matterofcommon and general knowledge in the art. The selection and timing ofthis camrning in the needle beds toaccomplish the sequence of knittingactions described in Fig. 2 is obvious and will not be described indetail here with the exception of a brief description to be presentedhereinafter to show the siniplicity of the invention as adapted tocircular machine operation with a plurality of yarn feeds.

With the 'foregoing'description in mind, the knitting sequence of Fig. 2will beself-explanatory.

Referring to Fig. 3, the yarn loops knitted by the dial needles areshown at 24 the yarn loops knitted by the cylinder needles are shownat21, and thc tuck strands are identified by the numerals 22 and 23. Thenumeral 22 designates the tuck strands produced by the dial needles andthe numeral 23 designates the tuck strands the back surface of thevalleys 26.

Fig. 4, being a photomicrographg' is self-explanatory. Some of the yarnfeeds carried black threads to facilitate identification of individualcourses. The product pictured in Fig. 4 is a photograph of the sameproductdiagrammaticallys'hown in Fig. 3 and the identifying nu-' meralshave the same meaning. 7

Fig. 5 is a flow-sheet of fabric treatment in accordance with theinvention and this flow-sheet is self-explanatory. The flow-sheetschematically illustrates the specific treatment utilized in thespecific illustration of the invention which will be presentedhereinafter.

Fig. 6 is a photomicrograph of the cleaned, dried and napped productproduced by the treatment indicated in Fig. 5. The numeral 27 indicatesthe nap on the ribs 25 and the numeral 28 indicates the nap on the outertuck strand.

Example The invention will now be illustrated in its presently preferredform employing a knitting machine of the circular type having a singlecylinder and a single dial each of which is provided with 12 needleslots per linear inch. The cylinder needles are 36 gauge and the dialneedles are 24 gauge.

The yarn used is a number 12 single yarn consisting of cotton. Reed #1(the middle dial tuck) has one end of 8 single yarn thereby raising theheight of the cell walls, feeds #2 to 7 inclusive use 12 single yarn.Mixtures of cotton with other fibers both natural and syn- .thetic mayalso be employed with success.

The needle arrangement used is the 2 x 2 needle positioning shown inFig. 1 and the knitting sequence followed is the specific sequenceindicated in Fig. 2.

The circular knitting machine is provided with 8 yarn feeds which areequally spaced around the periphery of the machine. Each yarn feedsupplies yarn-to both the dial and the cylinder needles. Considering theyarn feeds as being numbered 1 -8 consecutively, and'with theunderstanding that the yarn feeds circle the machine with the cams forthe dial and cylinder needles while the cylinder and-dial arestationary, the cams are constructed as follows: i

- The dial cams opposite yarn feeds 1, 2, and 8 are configurated to movethe needles which they pass through a tuck stitch sequence as previouslydescribed in detail. The dial earns opposite yarn feeds3, 4, 5, and 6are configurated to move the needles which they pass through aconventional knitting sequence as has also been previously described indetail.

The cylinder cams opposite yarn feeds 1, 2, 3, 7, and 8 are configuratedto move the needles which they pass through a conventional knittingsequence and the cylinder cams opposite yarn feeds 4, 5, and 6 areconfigurated to move the needles which they pass through a tuck stitchsequence.

As will now be appreciated, a conventional circular rib knitting machinehas been made to pursue continuously and without change in speed oroperation the knitting sequence of Fig. 2 by the simple expedient ofselecting and positioning the needle operating cams.

It has been found that the application of a heavy tension on the fabricproduced is beneficial in achieving fully satisfactory machineoperation.

The fabric produced is then passed throughascouring bath for the purposeof removing all foreign matter such as dirt, oil, paraffin, etc. Asuitable scouring bath which may be at the boiling point during scouringhas the following composition:

In place of the detergent specified above, any of the common detergentsanionic, cationic or non-ionic can be used. The detergent may be of thecommon anionic type .such as sodium lauryl sulfate, dioctyl sodiumsulfosuc- Parts by weight cinate, sodium oleate, and sodium or potassiumsalt of keryl benzene sulfonate (kerylrepresents a kerosene fractionof'from C-12 to C-18 carbon length used in alkylating benzene), thesodium or potassium salt of 0-12 to Cl8 alkyl naphthalene sulfonate, thealkali metal salt of sulfonated castor oil, etc.

Suitable cationic detergents are amine and quaternary ammonium saltscontaining hydrocarbon chains of 12 or more carbons, such as TritonX-400. Cetyldimethylammonium acetate is also suitable.

The amine salt is preferably one which is wholly aliphatic in nature andsecondary as well as tertiary amine salts are particularly effective.Such specific salts as saugryl dimethyl amine hydrochloride, oleyldimethyl amine sulfate and stearyl methyl amine sulfate are allsuitable.

Non-ionic detergents can also be employed, such materials includingglyceryl monolaurate, a sorbitol monooleate, sorbitol monostearate, andethylene oxide condensation products of each of these aforementionedhydroxy esters in which from one to all the hydroxy groups arecondensedwith one mole of ethyl hydroxy in the presence of an alkalinecatalyst.

The scoured fabric is then mangled to extract liquid from the same anddried on a conventional loop dryer.

The dried fabric is then napped or fleeced lightly first on one side andthen on the other side (the circular knitted fabric is turned insideout).

Rewet with water and then dry again in a fabric tumbling drum dryer. Thedried fabric was then finished by calendering on a Tube-Tex TensionlessCalender which is described in Textile Industries, April 1952.

The napping operation was performed on a Universal Napper Grinder whichis described in booket N-69 published by the Davis & Furber MachineCompany of North Andover, Mass. Another napping machine which can beused effectively is the 20 Roll Geared Double Action Napper described inDavis & Furber Bulletin N-66A.

If desired, the finished product may be run through mechanical shrinkageequipment after washing at any desired temperature.

The heat insulating cellular knitted fabrics of the invention are ofoutstanding utility where extreme warmth coupled with'light weight aredesired. These fabrics are, therefore, particularly adapted forunderwear intended for arctic use. However, the utility of the knittedfabrics of the invention is not limited in this regard and these fabricscan also serve as the basis for sweaters, dresses and other articles ofknitted outerwear.

The invention has been described to illustrate the con tinuousproduction ,of what might be considered to constitute yard goods. Theinvention is not limited in this regard since many variations can bemadewithout de-' parting from the invention as it has been described. Thus,for example, the invention can be performed in such manner as to providerib knitted culf portions.

If these cufi portions are desired, it isonly necessary to remove thetuck forming cams from the cylinder and modifications of the inventionlie within the skill of the art and are intended to be encompassed bythe'claims which follow.

I claim:

l. A heat insulating knitted fabric comprising a rib knitted fabrichaving longitudinally extending alternate ribs and valleys on both sidesthereof and longitudinally 7 spaced apart laterally extending groups ofadjacent tuck strands overlying the valleys and underlying the ribs ofsaid fabric, said ribs forming the side walls of air-entrapping cellsthe top and bottom walls of which are constituted by said tuck strands.

2. A heat insulating knitted fabric as recited in claim 1 in which saidtuck strands rise to a height which is less than the height of thecrests of th'e'adjacent ribs and in which said tuck strands extendacross at least two conventionally knitted yarn loops.

3. -A'he"at insulating knitted fabric as recited in claim 1 in whichsaid knitted fabric comprises fibrillatible yarn and said fabric isnapped to provide fibrillations extending from the surface of said ribsand said tuck strands.

4. A heat insulating knitted fabric as recited in claim 1 in which thetuck strands on opposite sides of said fabric are staggeredalongthelength of said fabric.

5. A method of forming a heat insulating knitted fabric havingair-entrapping cells on both sides thereof comprising knitting on a 'ribknitting machine having opposed needle banks a first plurality ofcourses with the needles of 'one of the .needle banks being operated toproduce conventional knit stitches and with the needles of the opposedneedle bank being operated to produce tuck stitches and then reversingthe sequence to knit a plurality o f courses with the needles of. saidfirst named needle bank being operated to produce tuck stitches whilethe needles of said "opposed needle bank are operated to produceconventional knit stitches.

"6. A method of forming a heat insulating knitted fabric havingair-entrapping cells on both sides thereof on a rib knittingmachine'having opposed needle banks comprising, providing said needlebanks with spaced apart groupsof needles, said groups of needles oneachof said needle banks being positioned between groups of needles on the,other of said needle banks, knitting a first plurality of courses withthe needles of one of knit stitches and alternately repeating said firstplurality of courses and said second plurality of courses.

11. A method of continuously forming a heat insulating knitted fabric asrecited in claim 10 in which all of the needles areoperated to produceconventional knit stitches for at least asingle course after said firstplurality of courses and after said second plurality of courses.

12. A method-of-continuously forming a heat insulating knitted fabric asrecited in claim '11 in which said first and said second plurality ofcourses are each constituted by three consecutive courses and a singlecourse in which all of the needles are operated to produce conventionalknit stitches after each of said plurality of courses.

13. A method of forming a heat insulating knitted fabric havingair-entrapping cells on both sides thereof on a rib knittingmachinehaving opposed needle banks comprising, providing, said opposedneedle banks with independently mounted 'knittingneedles positioned in 2X '2 rib knitting position, knitting three courses with the needles ofone of the needle banks being operated to produce conventiona'lk'nitstitches and with the needles of the opposed needle bank being operatedto produce tuck stitches, then knitting a single course of conventionalknit stitches with the needles of both of said needle banks, thenknitting threeflcourses with the needles of said first-named needle bankbeing operated to produce tuck stitches while the needles of saidopposed needle bank are operated to produce conventional knit stitches,then knitting a single course of conventional knit stitches with theneedles of both of said needle banks and then repeating the above setforth series of operations.

14. -A method 10f forming a heat insulating knitted fabric havingair-e'ntrapping cells on both sides thereof comprising knitting withfibrillatible yarn arib knitted fabrc having longiudinally extendingalternate ribs and valleys on both sides thereof and longitudinallyspaced the needle'banks being operated to'pro'duce conventional areoperated to produce conventional knit stitches for i at leasta." singlecourseafter said first plurality of courses and after 'saidsecondplurality of courses. 9 "8.A method of forming a heat insulatingknitted fabric as recited in clairn 6i n which the needles of saidneedle banks are positioned'toflassume a 2 x 2 rib knit position. I I

9. A method forming arheat insulating knitted fabric as recitedin claim7 in which the needles of said needle banks are positionedtoassume Ca 2x 2 rib knit position.

10. A method of continuously forming a heat insulat- A ing fabric havingair-entrapping cells on both sides thereof on a circular rib knittingmachine having a dial and a cylinder provided withjndependently mountedgroups of-knitting needles, said. groups of needleson said dial f l jldv yli b n'gpositioned between one another, knittinga'first pluralityof courses withthe needles of said dial being operated to produceconventional knit stitches and with'thenee'dles'of said cylinder beingop- -erated toproduce tuck stitchesand then knitting a sec-'on'd"plurality ofcourses with theneedles of said dial,

being operated to produce tuck stitches while the needles of saidcylinder are ..-,operated to produce conventional apart laterallyextending groups of adjacent tuck strands overlying the valleys andunderlying the ribs of said fabric, said ribsforming the side walls ofair-entrapping cells thetop and bottom walls of which are constitutedsaid tuck strands scourin'g the knitted fabric, drying the scouredfabric'and then napping said dried fabric.

15. A method of forming 'a heat insulating knitted fabric as recited inclaim 14 in which said scouring is performed by passing the knittedfabric through an aqueous bath containing a detergent to remove dirt,grease and" similar 'foreign' material.

16. A method of forming a heat insulating knitted fabric as recited inclaim 14 in which said tuck strands rise to a height which is less thanthe height of the crests of the adjacent'ribs and said napping operationproduces fibrillations at two different levels and in which saidtuckstrands extend across at least two conventionally knitted yarnloops.

17. A method 'of forming a heat insulating knitted fabric-as recited-invclaim 14in which both faces of said dried fabric are napped.

18. A method forming a heat insulating knitted fabric as recitedin claim14 inwhich said scoured knitted fabric is dried while said fabric istumbled.

References-Cited in the file of this patent UNITED STATES PATENTS r714,602 GreatiBritain Sept. 1,

